Immunoelectron microscopic localization of carcinoembryonic antigen in gastric adenocarcinoma cell lines

The distribution of carcinoembryonic antigen (CEA) in human gastric adenocarcinoma cell lines (HPE-GAC-3 cells and HPE-GAC-2 cells) was determined immunohistochemically by indirect peroxidase-labeled antibody method at the light and electron microscopic levels. In GAC-3 cells that proliferated as non-adherent single cells, CEA was located in the perinuclear spaces, the endoplasmic reticulum, Golgi apparatus, vesicles, multivesicular body (MVB) and entire plasma membrane. Membrane CEA was shown to be internalized into MVB in GAC-3 cells. In GAC-2 cells that form an acinus, CEA was predominantly present along the microvilli of the lumina) surface and in glycocalyceal bodies, the vesicles which bud from the microvilli into the lumen. These results suggest that in poorly differentiated cancer cells CEA is transported over the entire cell surface, retained on the membrane and accumulated Into the cell by way of the MVB, but in well differentiated cancer cells the newly synthesized CEA is rapidly and predominantly transported to the luminal surface and rapidly released from the membrane into the lumen by way of the glycocalyceal body.     

Retinoblastoma protein prevents staurosporine-induced cell death in a retinoblastoma-defective human glioma cell line.

OBJECTIVE: To investigate the mechanism of staurosporine-induced glioma cell death and cell cycle arrest using adenovirus-mediated gene transfection, as well as the function of retinoblastoma (Rb) and genetic instability induced by staurosporine. METHODS: Cell cycle regulation, cell death and nuclear abnormalities induced by staurosporine were examined using an adenovirus vector expressing Rb, p16 or p21 genes in human glioma cell lines. RESULTS: The Rb-defective SF-539 cell line was resistant to staurosporine compared with cell lines expressing intact Rb. SF-539 glioma cells exposed to staurosporine became multinucleated and then died. Multinucleation was prevented in SF-539 cells transfected with the Rb gene, thus decreasing the death rate of these cells. CONCLUSIONS: These results imply that enforced Rb expression protects cells from genomic instability induced by staurosporine regardless of its upstream molecular effects.     

Nucleotide deletion of T cell receptor V gamma 2 and J gamma 2 coding sequences at V gamma 2-J gamma 2 junctions in immature B cell lines.

Immature B cell lines transformed with a temperature-sensitive mutant of Abelson murine leukaemia virus undergo preferentially V gamma 2 to J gamma 2 joinings during culture at a non-permissive temperature (39 degrees C). Here we examined nucleotide addition and deletion at the V gamma 2-J gamma 2 junctions in these V gamma 2 to J gamma 2 joinings, in comparison with the V gamma 2-J gamma 2 junctional sequences reported previously in T cells. Forty-eight V gamma 2-J gamma 2 junctions were PCR-amplified and sequenced. Only three of 48 V gamma 2-J gamma 2 junctions had nucleotide addition. The average nucleotide deletion of V gamma 2 coding sequences at the V gamma 2-J gamma 2 junctions was 6.9 nucleotides in immature B cells and 5.1 nucleotides in T cells (p less than 0.05). Also, the average nucleotide deletion of J gamma 2 coding sequences at the V gamma 2-J gamma 2 junctions was 3.1 nucleotides in immature B cells and 1.9 nucleotides in T cells (p less than 0.01). The average of total number of the deleted nucleotides at the V gamma 2-J gamma 2 junctions was 10.0 nucleotides in immature B cells and 7.0 nucleotides in T cells (p less than 0.01). No correlation was found between the extent of the nucleotide deletion of the V gamma 2 coding sequence and that of the J gamma 2 coding sequence at each V gamma 2-J gamma 2 junction in immature B and T cells. These results demonstrated that nucleotide deletion at the V gamma 2-J gamma 2 junctions was significantly wider in immature B cells than in T cells.     

Vinyl polymerization. 294. Decomposition of tetramethyltetrazene in the presence of p-substituted benzyl chlorides

A study was made of the polymerization of acrylonitrile in dimethylformamide (DMF) initiated by the binary systems of tetramethyltetrazene (TMT) and p-substituted benzyl chlorides. The polymerization rate increased linearly with the σ-constants of substituents as electron-releasing groups were introduced to the phenyl ring of benzyl chloride. In order to elucidate the initiation mechanism of the polymerization, a kinetic investigation was also undertaken of the decomposition of TMT in the presence of p-substituted benzyl chlorides in DMF. The decomposition rate was first-order in TMT and first-order in p-substituents benzyl chloride. The decomposition rate also increased with the σ constants of substituents as electron-releasing groups were introduced. On the basis of the results, the initiation mechanism for the polymerization was discussed.     

HIGH-GRADE SURFACE OSTEOSARCOMA OF THE LEFT ILIUM A Case Report and Review of the Literature

A rare case of high-grade surface osteosarcoma of the left ilum is reported. Trephine biopsy performed on a 31-year-old woman suffering from a huge tumor of the left buttock revealed high-grade osteosarcoma, and hemipel-vectomy was undertaken. The surgical specimen showed that the tumor was present on the surface of the left ilium. Ten months after the operation, the patient died of brain metastasis. From these results, we considered this case to be one of high-grade surface osteosarcoma. ACTA PATHOL JPN 38: 235 -240, 1988.     

Long-lived polymer radicals, 2. An ESR study on the reactions of the propagating polymer radicals of N-methylacrylamide and N-methylmethacrylamide with vinyl monomers at room temperature

Acrylamide (AAm), methacrylamide (MAm), N-methylacrylamide (NMAAm) and N-methylmethacrylamide (NMMAm) were found to yield long-lived propagating polymer radicals in the photo-sensitized polymerizations in 1,4-dioxane or benzene. The concentration of poly(NMAAm) radicals reached 1.10^?3 mol/l. Some post-effect was observed at room temperature in the photo-sensitized polymerization of AAm with di-tert-butyl peroxide in 1,4-dioxane, while no post-polymerization proceeded at room temperature in the polymerization of NMMAm in benzene. The reactions of poly(NMAAm) and poly(NMMAm) radicals with various vinyl monomers were found to produce long-lived propagating polymer radicals of the second monomers at room temperature. Polymer radicals of non-homopolymerizable monomers such as α-methylstyrene and 1,1-diphenylethylene were easily formed in such a block-copolymerization matrix. The formation of the propagating polymer radicals of the vinyl monomers was investigated by means of ESR spectroscopy.     

Cellular niches controlling B lymphocyte behavior within bone marrow during development

In bone marrow, hematopoiesis is thought to depend on special microenvironments known as niches that maintain blood cells. However, the identity of niches and interaction of blood cells with niches remain poorly understood. Here we identify stage-specific cellular niches for B lymphopoiesis. The earliest precursors, pre-pro-B cells and end-stage B cells, plasma cells require CXC chemokine ligand (CXCL)12. CXCL12-expressing cells are a small population of stromal cells, scattered throughout bone marrow and located some distance from the cells expressing interleukin (IL)-7. Multipotent hematopoietic progenitors are attached to the processes of CXCL12-expressing cells and pre-pro-B cells adjoin their cell bodies. Maturer pro-B cells that require IL-7 have moved away and adjoin the IL-7-expressing cells. Plasma cells again seed CXCL12-expressing cells. We demonstrate the B lymphocyte characteristic location and movement between specific niches within bone marrow during development and suggest that CXCL12 maintains the cells in the niche.     

Protection of hepatocytes from apoptosis by a novel substance from actinomycetes culture medium

A novel substance, #675, found from an Streptomyces sp. SM675 culture medium, dose-dependently stimulates the proliferation of human functional liver cell 4 (FLC4). When FLC4 cells were incubated under conditions without fetal bovine serum (FBS), typical features of apoptotic cell death such as shrinkage and nuclear condensation appeared; high molecular weight (HMW) DNA fragments were found; and caspase-3 and poly (ADP-ribose) polymerase (PARP) proteins were cleaved. When FLC4 cells were incubated with #675 and without FBS, the cells grew healthy, no HMW DNA fragments were found, and caspase-3 and PARP cleavage weakened, suggesting that #675 protects FLC4 cells from apoptosis induced by FBS-deprivation. The quantitative reverse-transcribed polymerase chain reaction did not show differences in PARP or Bcl-2 mRNA expression in FLC4 cells incubated with or without #675, indicating other genes may be involved in this anti-apoptosis effect. These results show that #675 enhances FLC4 proliferation via an apoptosis-inhibition pathway, implying potential pharmacological and clinical applications.     

Correspondence of cue activity to reward activity in the macaque orbitofrontal cortex

It has been reported that neurons in the orbitofrontal cortex (OFC) respond to emotionally significant events such as reward-predicting cues and/or the reward itself. The responses to reward-predicting cues are considered to carry the information of the predicted reward. However, few studies have focused on the relationship of the neuronal activity during a cue period with that during a reward period. We can infer that the cue responses of OFC neurons are correlated to the reward responses if they carry the information of the predicted reward. In this study, we focused on neurons that showed responses during both the cue and reward periods, and compared the response characteristics between these periods. We found 94 of 369 OFC neurons showed significant responses during both the cue and reward periods, and 43 of which preserved their selectivity between these periods. Furthermore, population analysis showed that stronger cue responses corresponded to stronger reward responses, and stronger reward responses corresponded to stronger cue responses. These results suggest that individual neurons in the OFC associate visual information with reward information, and contribute to the prediction of future rewards by forming reward representations.